In 1996, Ariane 5 rocket blasted within minutes after take-off due to software bug. There was a conversion error from floating point to integer and that caused overflow exception in Ada.
Microsoft’s Zune player stopped working on December 31, 2008 because of a simple software bug. The software was written in such a way that it would never terminate if the year is leap year and the total number of days is 366.
S G Ganesh, Member Technical Staff, Siemens Corporate Technology, said at Bangalore (India) Spark IT 2010 show that software bugs should be treated as serious obstacles. They are just like ice-bergs because most of them are hidden. Only 1/10 th of all software bugs are known beforehand. Some trivial bugs may also pose dangerous down the road.
Software bugs are serious in nature and it is hard to tell the quality of the code. The first thing a programmer should realize about the cost of code quality. The next one is testing, but it is not the solution for creating good quality software. Testing only shows that the bug is present in the software, but, not their absence. For 99.9 per cent of inputs the bugs would go undetected during testing. It is also not fair to blame only the developers for software failures. Managers should also take equal responsibility.
source : http://blog.taragana.com/index.php/archive/a-software-bug-may-kill-you/